(a) Technical Field
The present invention relates to a plasma reactor having multi discharging tubes, and more particularly, to a plasma reactor having multi discharging tubes through which activated gas containing ion, free radical, atom and molecule is generated through plasma discharging, and different process gases are injected into multi discharging tubes in which solid, power and gas, etc., are plasma-treated with the activated gas to perform processes including cleaning process for semiconductor, and a plasma state can be maintained even at low power.
(b) Background Art
Generally, a plasma discharging has been used for exciting gas to generate activated gas containing ion, free radical, atom and molecule. The activated gas is used widely in various fields, representatively in semiconductor manufacturing process, for example etching, deposition, cleaning and ashing, etc.
Recently, wafer or LCD glass substrate for manufacturing semiconductor device has become much larger, and thus it is requested a plasma source which has a higher control ability of plasma ion energy, a treatment ability of a large area and easy expandability.
Further, it has been known that remote plasma is used efficiently for manufacturing semiconductor by using plasma. For example, the remote plasma is used for cleaning a process chamber or ashing to strip photo-resist.
The remote plasma reactor (or called as a remote plasma generator) may use a Transformer Coupled Plasma Source (TCPS) or an Inductively Coupled Plasma Source (ICPS).
The remote plasma reactor using the transformer coupled plasma source has a reactor body of a toroidal structure to which a magnetic core provided with a first wound coil is equipped. The remote plasma reactor using the inductively coupled plasma source has a reactor body of a hollow tube structure to which an inductively coupled antenna is equipped.
However, in case of the remote plasma reactor using the transformer coupled plasma source, it is operated at a comparatively high voltage environment due to its characteristics and thus it is extremely difficult to ignite plasma or maintain the ignited plasma at a low voltage environment.
Further, in case of the remote plasma reactor using the inductively coupled plasma source, it can be operated at a comparatively low voltage environment due to its characteristics whereas a supply power has to be increased for operating the remote plasma reactor and in this case the inside of the reactor body may be damaged due to ion impact.
In addition, a remote plasma reactor that is operated efficiently at a high or low voltage is required in accordance to various demands requested from semiconductor manufacturing process; however, a prior remote plasma reactor adapting one of the transformer coupled plasma source or the inductively coupled plasma source is not appropriately responded to the demands.
Furthermore, as the process target-substrate becomes large, the process chamber becomes large and thus a plasma source that can supply sufficiently and remotely high density activated gas is demanded.
Meanwhile, a substrate treating system is provided, in which two or more process chambers are provided in parallel in order to treat two or more process target-substrates in parallel for increasing production efficiency of a semiconductor device. At this time, when the remotely activated ion gas is supplied to two or more process chambers, plasma reactors have been equipped separately to the respective process chambers. However, in this case, equipment cost is increased and operation cost becomes high.
However, when single plasma reactor is used for supplying the activated ion gas to two or more process chambers, a plasma reactor of a large capacity has to be used but ionized gas of a large capacity is difficult to be generated and supplied by using an existing plasma reactor.
Further, the different kinds of process gases are ionized more efficiently by separating them than by mixing them in accordance to the semiconductor manufacturing process; however, it is difficult to perform it in a single process chamber.
Meanwhile, the existing plasma reactor, specially the transformer coupled plasma source has a problem that power greater than a predetermined level (for example, 3 kw) has to be supplied to maintain plasma and when the power becomes to the predetermined level or less, the plasma cannot be maintained.